'\" te
.\" Copyright (c) 2012, Joyent, Inc.
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.TH HYPRLOFS 4FS "March 7, 2012"
.SH NAME
hyprlofs \- fast name space virtual file system
.SH SYNOPSIS
.LP
.nf
#include <sys/fs/hyprlofs.h>

\fB\fR\fBmount\fR (\fB\fR\fIspecial\fR, \fB\fR\fIdirectory\fR, \fB\fR\fIMS_DATA\fR, \fB\fR\fI"hyprlofs"\fR, \fB\fR\fINULL\fR, \fB\fR\fI0\fR);
.fi

.SH DESCRIPTION
.sp
.LP
\fBhyprlofs\fR is a hybrid file system combining features from
\fBtmpfs(4FS)\fR and \fBlofs(4FS)\fR.
As with \fBlofs\fR, the \fBhyprlofs\fR file system allows new, virtual file
systems to be created which provide access to existing files using alternate
pathnames.  In addition, the files themselves may have alternate names and
paths within the mount.
Unlike \fBlofs\fR, files cannot be created and backing files cannot be removed.
The name space is completely managed through ioctls on the mount.
Entries in the name space are not mounts and thus, they will not appear in the
mnttab.  The file system is designed to provide a very fast name space to the
backing files.  The name space can be modified very quickly through the ioctl
interface.
.sp
.LP
\fBhyprlofs\fR file systems can be mounted with the command:
.sp
.in +2
.nf
\fBmount \fR\fB-F\fR\fB hyprlofs swap \fR\fIdirectory\fR
.fi
.in -2

.sp
.LP
The name space used by \fBhyprlofs\fR exists only in-memory so it will consume
a small amount of the system's virtual memory.  The files themselves are backed
by the original file as with \fBlofs\fR.

.SH SEE ALSO
.sp
.LP
\fBmount\fR(2), \fBumount\fR(2),
\fBdf\fR(8), \fBmount\fR(8), \fBswap\fR(8)
.sp
.LP
\fISystem Administration Guide: Basic Administration\fR
.SH DIAGNOSTICS
.sp
.LP
\fBdf\fR(8) output is of limited accuracy since
the space available to \fBhyprlofs\fR is dependent on the swap
space demands of the entire system and the files in the name space are not
included.
